Q. I live in a small nine-unit co-op. Last year, my co-op spent $250,000 to fix several water problems. The work was extensive and included replacing the roof. We took out a loan, which strained our finances and raised our maintenance.

This summer the owner of the top-floor unit received approval to have her bathrooms renovated. We recently discovered that she also installed central air, which she had not asked permission to do. The project involved punching holes in our new roof, violating our warranty. We are having the damage assessed and have demanded that she remove the air-conditioning and pay to restore the roof.

This owner has not lived in the building in the last 13 years. She plans to move back, but she does not know many people in the building. Because we are a small building, we are a close-knit community. Her actions have infuriated everyone. Given the damage she has created and the unscrupulous way she attempted to have the work done, is it possible for us to force her to sell the apartment? Besides paying for damages, do we have any other options?

Chelsea, New York

A. As frustrating as it might be, disliking someone is not cause for eviction.

You should, however, insist that the wayward shareholder pay to fix the damage. To make sure the repairs are done to the building’s satisfaction, the board should handle the work and make the shareholder foot the bill. Given that she’s about to live under that very roof, she’ll very likely pay up.

“She’s not going to want a million enemies if she’s moving back in,” said Steven D. Sladkus, a Manhattan co-op and condominium lawyer. “It would behoove her to pay for all the repair charges with a smile on her face.”

Word that the prodigal neighbor is coming home might actually provide a rare opportunity to mend fences — or in this case, a roof. Perhaps Miss Absentee had no idea that her contractor planned to make Swiss cheese of the roof, or that her neighbors would get so angry about it.

Since neighborly harmony seems to be a priority, consider mediation. The service is free in New York City and not legally binding. Face-to-face negotiations have been known to bring about peace, even in a co-op. The city’s Civil Court system has information on mediation on its website at: nycourts.gov/courts/nyc/civil/services.shtml

“Co-op disputes are like the Middle East rift on a small scale,” said Brad Heckman, the chief executive of the New York Peace Institute, a mediation service. But “once people get to know each other a little bit, they are able to come up with creative solutions that can satisfy everybody.”

Horrible Hoarder

Q. I am a shareholder and resident in a New York City co-op building. My immediate neighbor has a significant hoarding problem, evidenced by vermin, odors, and extreme accumulation of garbage within her unit that I have personally witnessed and photographed. Not only am I concerned about her health and safety, I would also like to know my rights, as the condition of her unit is having an effect on my ability to live in my home. I believe the co-op may have begun legal proceedings against her, but the management company will not give me any specific information. Am I entitled to know about any court proceedings?

Clinton Hill, Brooklyn

A. It’s unlikely your neighbor means you harm, as hoarding is a mental illness, but her behavior has turned your home into an extension of her trash bin — and the building needs to resolve the problem.

“A hoarder has the right to hoard possessions,” said David Tolin, the director of the Anxiety Disorders Center at the Institute of Living and author of “Buried in Treasures” (Oxford University Press, 2007), “but her neighbor has a right to live safely and comfortably.”

An error has occurred. Please try again later.

You are already subscribed to this email.

You could report the situation to 311 and the building would probably receive a code violation. But going this route as a first step might work against you: A violation won’t make your neighbor stop her compulsive behavior, but it will irk management.

“Even if you’re absolutely in the right,” said Elliot Meisel, a partner in the law firm Brill & Meisel, “you’ve made yourself the issue instead of making the board focus on what they should be doing.”

The building management doesn’t have to tell you what it’s up to, but you could find out anyway. Channel your inner Matlock and check the courthouse or online to see what cases your building might be involved in, since ongoing litigation is public record. First, write a polite but firm letter to the board letting it know that if it does not remedy the situation — or at least clue you in on its plans — you will talk to the city. Sometimes, a little pressure goes a long way.

Barbershop Blues

Q. I live in a rent-stabilized apartment on the second floor of a five-story walk-up building built in 1910, which currently has a barbershop on the ground level. The barbershop, which moved into the store two years ago, has recently started playing loud bass music. No modifications or improvements were made to soundproof the store. Banging bass noise and vibrations travel from the store to every room in my apartment. I am retired and home during the day, and find these constant loud, pervasive bass sounds for up to 10 hours a day, seven days a week, not only stressful, but bad for my hearing and a cause of headaches. The barbershop’s owners have refused my requests to move the speakers, which are mounted on the walls near the ceiling and heating pipes to the floor, or to lower the bass.

I filed a complaint with the landlord, and his agent said there was nothing they could do. The barbershop’s lease says it can play music as loud as it wants to from 7 a.m. to 10 p.m. I also filed a complaint with 311, but because the noise is during business hours they could not help me. I feel my requests to lessen the bass noise and vibration coming into my apartment are reasonable and something should be done to soundproof the ceiling and walls in the store.

Upper East Side, New York

A. I’m not sure what the business model is behind a barbershop that blasts music day and night. Do they hope to drown out the complaints from patrons dissatisfied with a buzz cut? But even if the owner’s affinity for a heavy bass line has doubled his foot traffic, it does not make his actions appropriate or legal. The noise has already caused you physical pain. It might also damage your heart, as the World Health Organization has linked noise pollution (from traffic) to cardiovascular disease.

“It’s not just callous on the part of the business, but it is violating fundamental rights” of the tenants, said George Prochnik, the author of “In Pursuit of Silence: Listening for Meaning in a World of Noise” (Anchor, 2011). “This isn’t just a quality-of-life issue, but a health issue.”

Give 311 another call. The city has a dizzyingly complex noise code, with enforceable rules. Ask if your complaint has arrived at the Department of Environmental Protection yet. An agency inspector should visit your apartment to check the decibels emanating through your floor. Request that the inspector also check for bass vibrations, since bass is tested with a meter designed to pick up those frequencies.

If the noise is over the legal threshold, the department will work with the barbers to bring them into compliance. If that doesn’t work, it can also slap them with a violation, which might get them to tone down the music. Even if it’s not over the legal limit, you might have a claim against your landlord for allowing your home to become the proverbial nightclub, according to Jeffrey Reich, a real estate lawyer at Wolf Haldenstein Adler Freeman & Herz.